BRITISH SLUGS 



1085 



formed " keel " the whole length of the 

 back ; but the " shield " was marked 

 with concentric hnes, and respiratory 

 oritice posterior. The colour, a uniform 

 pale grey, lighter on the sides, with darker 

 markings on the " shield," with the 

 " tentacles " a dark slate-grey ; the 

 length about half an inch. The movement 



frequents stiff clay soil in gardens, lying 

 in worm-burrows during the day. 



Although I have made no reference to 

 the anatomical structure of the slug tribe, 

 as not being of general interest, the con- 

 sideration of the mouth of the animal 

 is worth a few words. Unless slugs have 

 been stuched in captivity, it may not be 



ARION ATER VAR. SHOVING BLENDED COLOURING OK 

 GREENISH GREY WITH ORANGE FOOT-FRINGE. 



was as rapid a day old as that of a full- 

 grown slug. 



Milax gagates, when resting, contracts 

 more into the rounded form than any 

 other British Limax. L. maximus and 

 L. flavus he curled head to tail in the 

 fashion of a dog, the detached " shield " 

 border lying out in a way suggestive of a 

 dog's ears. 



The variety M. Sowerhii shows the 

 " keel " paler than the body, most 

 prominent on the back, and disappearing 

 towards the tail. The colouring is grey, 

 tinged with yellow, as small pigmented 

 cells that show as dots; the "keel" is 

 amber-coloured, and the " shield " granu- 

 lated in surface as the Arionidce. It 



known that you can distinctly hear them 

 feeding ; and watch the deliberate series 

 of circular bites enlarging the gap in a 

 lettuce leaf. Regular sharp httle sounds 

 are made with precision at each bite, and 

 with each movement the mouth can be 

 seen opening as a dark cavity between 

 the two curved " Hps." 



The slug is possessed of what is termed 

 a " lingual ribbon " or jaw plate, that is 

 set with exceechngly fine sharp teeth. The 

 variations between species is determined 

 in exact study of the subject under the 

 microscope, when these jaw and teeth 

 variations from typical form art' taken 

 into consideration. 



Maud U. Clarke. 



